1021020002001 has 12 divisors (see below), whose sum is σ = 1474975931520. Its totient is φ = 680601880440.

The previous prime is 1021020001997. The next prime is 1021020002003. The reversal of 1021020002001 is 1002000201201.

It is not a de Polignac number, because 1021020002001 - 2² = 1021020001997 is a prime.

It is a super-2 number, since 2×1021020002001² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1021020002003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6427245 + ... + 6584186.

It is an arithmetic number, because the mean of its divisors is an integer number (122914660960).

Almost surely, 2^{1021020002001} is an apocalyptic number.

It is an amenable number.

1021020002001 is a deficient number, since it is larger than the sum of its proper divisors (453955929519).

1021020002001 is a wasteful number, since it uses less digits than its factorization.

1021020002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13020156 (or 13020153 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1021020002001 its reverse (1002000201201), we get a palindrome (2023020203202).

The spelling of 1021020002001 in words is "one trillion, twenty-one billion, twenty million, two thousand, one".